Circuit breaker



June 1, 1943. w, H. FRANK ETAL 2,320,355

cmcum BRE-A-KER Original Filed Aug 4, 1957 zfi ATTORNEY.

Patented June 1, 1943 CIRCUIT BREAKER William 1!. Frank and Elwood '1. Platz, Detroit,

asslgnors to Bulldog Electric Products Com- :lamny, Detroit, Mich., a corporation of West Vir- Refllcd for abandoned application Serial No.

157,268, August 4, 1937. This application Januan 19, 1940, Serial No. 314,731

25 Claims.

This application relates to circuit breakers and is a substitute for an application, Serial No. 157,268, flied August 4, 1937.

A particular object is to provide, in a circuit breaker, a novel contact actuating mechanism, the same including a floating bar to which is pivotally connected 8. contact arm, a handle bearing directly on the bar, a compression spring bearing directly on the contact arm, with the bar and the contact arm moving in unison generally but with each moving independently of the other to a limited extent.

A further object is to provide, in such a breaker,

a positive return. means in the nature of a lug formed on the floating bar whereby, in the event the floating bar and contact arm are not caused to move to off position by the spring following overload release of the bar, the handle may be manipulated to cause the parts so to move positively.

A still further object is to provide, in such a breaker, a magnetic loop in the form of a flexible connection between the bimetal Warping element of the breaker and the contact arm whereby the magnetic effect in the loop will enhance the warping effect of the bimetal element.

A still further object is to provide a novel form of breaker housing, the same comprising sheets or laminae of insulation.

A further object is to provide a circuit breaker generally resembling that shown in the application of Lyman 0. Fisher, Serial No. 133,949, now Patent No. 2,154,237, of April 11, 1939, of March 31, 1937, but differing therefromin details of construction resulting in improvement in manufacture and operation of the breaker.

Still further objects will presently be understood upon reference to the appended drawing. In this drawing,

Fig. 1 is a section as if on line l-l of Fig. 2, showing theparts in "on position;

Fig. 2 is a section as if on line 2-2 of Fig. 1;

Fig. 3 resembles Fig. 1 except that the parts are shown in ofi" position;

Fig. 4 resembles Fig. 1 except that the parts are shown in the position they have following the initial part of the trip movement;

Figs. 5 and 6 show the floating bar and the contact arm respectively.

Referring to the drawing, it will be observed that the breaker hereof comprises a housing which is formed of sheets or laminae of insulation. Each sheet, as necessary, is cut out so that when the sheets are placed together, as shown in Fig. 2, cutouts will register to form appropriate cavities within the-housing.

Trunnioned in holes of the housing is an axle pin l I which forms an axle for the breaker handle l2 whose lower end It is shown as engaging the upper surface of a floating bar I5 having lugs l6 slidably disposed in slots 11 within the housing whereby the floating bar may move up and down in a guided path. A downwardly projecting tonguel8 of the bar projects through a slot [9 of a contact arm 20 on whose end is a contact 2|. Knife edged shoulders 22 of bar l5 seat within V-shaped portions 23 of the contact arm to form a knife-edged pivotal connection between the contact arm and the floating bar.

Contact 2| is adapted to make with or break from a stationary contact 24 of the breaker.

A compression spring 26 has one end seated in the breaker housing and the other end pushing upwardly against an end of the contact arm 20.

Anchored at its free end to the housing and within the housing is a bimetal warping element 28 whose free end is adjacent the free end 29 01 the floating bar and is electrically connected bar has not already been moved up by the action of the spring 26, following overload release of the bar.

The operation of the breaker will readily be understood. When the handle is moved from "on (Fig. 1) to oii" (Fig. 3), contact arm 20 and floating bar IE will move upwardly.

Return movement of the handle will return the parts, against the influence of spring 26, to the position of Fig. 1.

On overload, due to the magnetic effect provided by loop 30 and to the inherent warping effect of the bimetal element 28, the latter will warp to the right releasing end 29 of the floating bar l5. Spring 26 will then cause the bar l5 and the contact arm 20 to move upwardly, as a unit, to the position of Fig. 4, opening the circuit, these parts pivoting about handle portion ll. The line of force of spring 26, initially to the left of handle Pi t l shifts to the right of handle pivot ll thereupon and passes over center or plvot' ll causing a counter-clockwise rotation of the handle, provided, of course, the handle not be held against such rotation, resulting in the handle moving to the off position of Fig. 3, whereupon the floating bar I5 continues its movement from the position of Fig. 4 upwardly to that of Fig. 3, movement of all the parts terminating with the parts in such position, which is consequently not only the normal off position, but also the final tripped position. Now having described the breaker hereof, reference will be had to the claims which follow:

We claim:

1. In a circuit breaker, a floating bar, a contact arm pivotally connected thereto by a pivot of the knife edge bearing type, a spring biasing the arm, a handle for causing movement of the bar and directly engaging the bar, and a latch for holding the bar and directly engaging the bar.

' 2. In a circuit breaker, a floating bar, a stationary contact, a movable contact arm having a portion for engaging the stationary contact, a spring, a handle, and a latch, the foresaid parts being so arranged and interconnected that when the arm is in contact making engagement with the stationary contact, the handle form a fixed fulcrum or pressure point for the arm, and the spring biases the arm about such fulcrum or pressure point and into pressure engagement with the stationary contact, release movement of either the latch or the handle permitting movement of the parts, caused by the force of the spring, for circuit opening. i

3. In a circuit breaker, a floating bar, a sta-' tionary contact, a movable contact arm having a portion for engaging the stationary contact, a spring, a handle, and a latch, the aforesaid parts being so arranged and interconnected that when the arm is in contact making engagement with the stationary contact, the handle forms a fixed fulcrum or pressure point for the bar, the latch holds one end of the'bar immovable and pressed against it whereby the other end forms a fixed fulcrum or pressure point for the arm, and the spring biases the arm about such fulcrum or pressure point and into pressure engagement with the stationary contact, release movement of either the latch or the handle permitting movement of the parts, caused by the force of the spring, for circuit opening, the bar and the arm being alongside each other for at least part of their extent, with the contact making part of the arm being at that end of the arm most remote from the bar, and with the latch held part of the bar being most remote from the arm, and with the spring and handle being between the latch and the contact making part of the arm.

4. In a circuit breaker, a floating bar, a stationary contact, a movable contact arm having a portion for engaging the stationary contact, a spring, a handle, and a latch, the aforesaid parts being so arranged and interconnected that when the arm is in contact making engagement with r the stationary contact, the handle forms a fixed fulcrum or pressure point for the bar, the latch holds one end of the bar immovable and pressed against it whereby the other end forms a fixed fulcrum or pressure point for the arm, and the spring biases the arm about such fulcrum or pressure point and into pressure engagement with the stationary contact, release movement of either the latch or the handle permitting movement of the parts, caused by the force of the spring, for circuit opening, the bar and the arm their extent, with the contact making part of the arm being at that end of the arm most remote from the bar, and with the latch held part of the .bar being most remote from the arm, and with the spring and handle being between the latch and the contact making part of the arm, and arranged on opposite sides of'the arm and bar.

5. In a circuit breaker, a floating bar, a stationary contact, a movable contact arm having a portion for engaging the stationary contact, a spring, a handle, and a latch, the aforesaid parts being so arranged and interconnected that when the arm is in contact making engagement with the stationary contact, the handle forms a fixed fulcrum or pressure point for the bar, the latch holds one end of the bar immovable and pressed against it whereby the other and forms a fixed fulcrum or pressure point for the arm, and the spring biases the arm about such fulcrum or pressure point and into pressure engagement with the stationary contact, release movement of either the latch or the handle permitting movement of the parts, caused by the force of the spring, for circuit opening, the bar and the arm being alongside each otlier for at least part of their extent, with the contact making part of the arm being at that end of the arm most remote from the bar, and with the latch held part of the bar being most remote from the arm, and with the spring and handle being between the latch and the contact making part of the arm, the arm and bar, though being relatively movable slightly, being arranged to move in unison to and from circuit closing position.

6. In a circuit breaker, a floating bar, a stationary contact, a movable contact arm having a portion for engaging the stationary contact, a spring, a handle, and a latch, the aforesaid parts being so arranged and interconnected that when the arm is in contact making engagement with the stationary contact, the handle forms a fixed fulcrum or pressure point for the bar, the latch holds one end of the bar immovable and pressed against it whereby'the other end forms a fixed fulcnun or pressure point for the arm, and the spring biases the arm about such fulcrum or pressure point and into pressure engagement with the stationary contact, release movement of either the latch or the handle permitting 'movement of the parts, caused by the force of the spring, for circuit opening, the bar and the arm being alongside each other for at least part of their extent, with the contact making part of the arm being at that end of the arm most remote from the bar, and with the latch held part of the bar being most remote from the arm, and with the spring and handle being between the latch and the contact making part of the arm, and arranged on opposite sides of the arm and bar, the arm fulcrum provided by the bar being between the arm contact and the spring, whereby the spring, though having a constant tendency to move the spring engaged part of the arm away from the, stationary contact, actually operates to bias the contact end of the arm into pressure engagement with the stationary contact when the bar is held by the latch and handle.

7. In a circuit breaker, a stationary contact, a floating element consisting of a bar and an arm arranged alongside each other and overlapping for part of their extent and having at one end a contact for engaging the stationary QOntact, and having at the other end a. latch for holding the element, a spring and a handle, both the spring and handle being between the latch and the contact, the spring having a constant tendency to bias the element away from thestationary contact and operating, because the bar, when held by the latch and handle,

, forms a fulcrum for the arm between the spring and contact, to bias the arm contactinto pressure engagement with the stationary contact.

8. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means biasing the spring engaged portion of the means in the direction which is away from the stationary contact, and a handle engaging the means between the spring and the latch, the parts being so mounted and constructed that when the handle is in one position it pushes the handle engaged part of the "means in the direction towards the stationary contact, against the spring force which at that time pushes the movable contact against the stationary contact, and the means against the latch, with the spring holding the handle and the parts in that position, and when the handle is moved from that position, it permits the spring to bias the means to such a position that its movable contact is separated from the stationary contact, to hold the handle in the second named position, and to hold the means in engagement with the latch, and when the latch releases, the spring causes contact separation.

9. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means biasing the spring engaged portion of the means in the direction which is away from the stationary contact, and a handle engaging the means between the spring and the latch, the parts being so mounted and constructed that when the handle is in one position it pushes the handle engaged part of the means in the direction towards the stationary contact, against the sprin force which at that time pushes the movable contact against the stationary contact, and the means against the latch, with the spring holding the handle and the parts in that position. and when the handle is moved from that position, it permits the spring to bias the means to such a position that its movable contact is separated from the stationary contact, to hold the handle in the second named position, and to hold the means in engagement with the latch, and when the latch releases, the spring causes contact separation, the parts further being so constructed that thereafter, the spring causes the handle to move automatically, if and when it is free to move. from the first named-position to the second, and also causes the means again toengage the latch.

10. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means biasing-the spring engaged portion of the means in the direction which is away from the stationary contact, and a handle engaging the means between the spring and the latch, the parts being so mounted and constructed that when the handle is in one position it pushes the handle engaged part of the means in the direction towards the stationary contact, against the spring force which at that time pushes the means so that the spring engaged portion of the means tends to move in the direction which is away from the stationary contact, and also pushes the means against the latch, with the spring holding the handle and the parts in that position, and when the handle is moved from that position, it permits the spring to bias the means to such a position that its movable contact is separated from the stationary contact, to hold the handle in the second named position, and to hold the means in engagement with the latch, and when the latch releases, the spring causes contact separation.

11. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a, spring between the ends of the means biasing the spring en gaged portion of the means in the direction which is away from the stationary contact, and a handle engaging the means between the spring and the latch, the parts being so mounted and constructed that when the handle is in one position it pushes the handle engaged part of the means in the direction towards the stationary contact, against the spring force which at that time, pushes the means so that the spring engaged portion of the means tends to move in the direction which is away from the stationary contact, and also pushes the means against the latch, with the spring holding the handle and the parts in that position, and when the handle is moved from that position/it permits the spring to bias the means to such a position that its movable contact is separated from the stationary contact, to hold the handle in the second named position, and to hold the means in engagement with the latch, and when the latch releases, the spring causes contact separation the parts further being so constructed that thereafter, the spring causes the handle to move automatically, 'if and when it is free to move, from the first named position to the second, and also causes the means again to engage the latch. 12. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means for biasing the means,

. and a handle engaging the means between able contact for engagement with the stationary contact when that end of'the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means for biasing the means, and ,a handle engaging the means between the spring and the latch, and opposing the spring.

14. In a circuit breaker, a contact, a bar whose movement controls movement of the contact and to which the contact is operatively connected, a handle and a spring arranged to bias the bar in opposite directions, and a lug on the bar arranged to be engaged by the handle whereby,.in emergencies, the handle may be manipulated to pull the bar in the direction of the bias thereon of the spring, the bar comprising two overlapping plates, each of which has an end pivotally engaging the .other, the ends being spaced, the spring bearing directly one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate carrying the contact, and the second mentioned plate carrying the lug.

15. An automatically releasing circuit breaker having an actuated part, a spring biasing means and an overload, latch therefor, and a handle for moving the part to and from on" and "011? positions and for relatching the part after an overload release thereof; the parts being so arrangedthat on an overload release of the latch, the spring moves the part out of on position,

and into a trip position, trip free of the handle,.

and then moves thev part into off position and the handle out of on" position, if the handle is not held manually, or when the handle is released, in case it was held manually during the overload release movement of the part, the part comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a, contact portion and the second mentioned plate engaging the latch.

16. An automatically releasing circuit breaker having an actuated part, a spring biasing means and an overload latch therefor, and a handle for moving the part to and from on" and off positions and for relatching the part after an overload release thereof, the parts being so arranged that on an overload release of the latch, the spring moves the part out of on position, and into a trip position, trip free of the handle, and then moves the part into 0115" position and the handle out of on position, if the handle is not held manually, or when the handle is released, in case it was held manually during the overload release movement of the part, the handlebeing so constructed as to push or cam the part into "on position when it is moved to on" position, and to release the part for movement by the spring when it is moved out of on position, the part comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch.

17. An automatically releasing circuit breaker having an actuated part, a, spring biasing means the spring moves the part out of "on" position,

and into a "trip position, trip free of the handle, and then moves the part into off position and the handle out of "on position, if the handle is not held manually, or when the handle is released, in case it was held manually during the overload release movement of the part, the handle being so constructed as to push or cam the part into "on position when it is moved to "on" position, and to release the part for movement by the spring when it is moved out of "on" position, there being a formation on the part enabling it to be moved by the handle out of "trip position and into "off position, whereby, in the event the spring fails to move the part out of "trip and into off position and fails to move the handle from on to oil position, the ham dle may be manipulated so to do, by being moved from the on" position to the "oif position, the part comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch, the formation being on the first mentioned plate.

18. An automatically releasing circuit breaker having an actuated part, a spring biasing means and an overload latch therefor, and a handle for moving the part to and from on and "off positions and for relatching the part after an overload release thereof, the parts being so arranged that on an overload release of the latch,

the spring moves the part out of on position, and into a trip position, trip free of the handle, andthen moves the part into "off" position and the handle out of "on position, if the handle is not held manually, or when the handle is released, in case it was held manually during the overload release movement of the part, the actuated part comprising a floating bar having a latch connection at one end about which it 7 I pivots on normal handle actuation and adapted to' be engaged by the handle between its ends, the bar comprising two overlapping plates, each of which an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch.

19. An automatically releasing circuit breaker having an actuated part, a spring biasing means and an overload latch therefor, and a handle for moving the part to and from on and "off positions and for relatching the part after an overload release thereof, the parts being so arranged that on an overload release of the latch, the spring moves the part' out of "on position, and into a trip" position, trip free of the handle, and then moves the part into off position andthe handle out of on" position, if the handle is not held manually, or when the handle is released, in case it was held manually during the overload release movement of the part, there being a, formation on the part enabling it to be moved by the handle out of "trip" position and into off position, whereby, in the event the spring fails to move the part out of "trip and into of! position and fails to move the handle from on" to off position, the handle may be manipulated so to do, by being moved from the "on position to the "ofi position, the part comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch, the formation being on the first mentioned plate.

20. An automatically releasing circuit breaker having an actuated part, a spring biasing means and an overload latch therefor, and a handle for moving the part to and from on and "off" part into on position when it is moved to on position, and to release the part for movement by the spring when it is moved out of on position, the actuated part comprising a floating bar having a latch connection at one end about which it pivots on normal handle actuation and adapted to be engaged by the handle between its ends, the bar comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch.

21. An automatically releasing circuit breaker having an actuated part, a spring biasing means and an overload latch therefor, and a handle for moving the part to and from on" and off" positions and for relatching the part after an overload release thereof, the parts being so arranged that on an overload release of the latch, the spring moves the part out of on position, and into a trip" position, trip free of the handle, and then moves the part into oif position and the handle out of on position, if the handle is not held manually, or when the handle is released, in case it was held manually during the overload release movement of the part, the handle being so constructed as to push or cam the part into on" position when it is moved to on position, and to release the part for movement by the spring when it is moved out of on position, there being a formation on the part enabling it to be moved by the handle out of "trip" position and into off position, whereby, in the event the spring falls to move the part out of trip and into off" position and fails to move the handle from on to oil position, the handle may be manipulated so to do, by being moved from the "on" position to the "off" posi- .the bar comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch, the formation being on the first mentioned plate.

22. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means biasing the spring engaged portion of the means in the direction which is away from the stationary contact, and a handle engaging the means between the spring and the latch, the parts being so mounted and constructed that when the handle is in one position it pushes the handle engaged part of the means in the direction towards the stationary contact, against the spring force which at that time pushes the means so that the spring engaged portion of the means tends to move'in the direction which is away from the stationary contact, and also pushes the means against the latch, with the spring holding the handle and the parts in that position, and when the handle is moved from that position, it permits the spring to bias the means to such a position that its movable contact is separated from the stationary contact, to hold the handle in the second named position, and to hold the means in engagement with the latch, and when the latch releases, the spring causes contact separation, the means comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch.

23. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that endof the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means biasing the spring engaged portion of the means in the direction which is away from the stationary contact, and a handle engaging the means between the spring and the latch, the parts being so mounted and constructed that when the handle is in one position it pushes the handle engaged part of the means in the direction towards the stationary contact, against the spring force which at that time pushes the means so thatthe spring engaged portion of the. means tends to move in the direction which is away from the stationary contact, and also pushes the means against the latch, with the spring hiding the handle and the parts in that position, and when the handle is moved from that position, it permits the spring to bias the means to such a position that its movable contact is separated from the stationary contact, to hold the handle in the second named position, and to hold the means in engagement with the latch, and when the latch releases, the spring causes contact separation, the parts further being so constructed that thereafter, the spring causes the handle to move automatically, if and when it is free to move, from the first named position to the second, and also causes the means again to engage the latch, the means comprising two overlapping plates, eachot which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch.

24. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary contact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement of that end thereof in the direction which is towards the stationary contact, a spring between the ends 01' the means for biasing the means, and a handle engaging the means between the spring and the latch, the means comprising two overlapping'plates, each of which has an end pivotally engaging the other, the ends being spaced, the-spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first mentioned plate having a contact portion and the second mentioned plate engaging the latch.

25. An automatically releasing circuit breaker having a stationary contact, an elongated actuated means provided at one end with a movable contact for engagement with the stationary con- 4 tact when that end of the means is pushed towards the stationary contact, a latch for the other end of the means restraining movement .of that end thereof in the direction which is towards the stationary contact, a spring between the ends of the means for biasing the means, and

a handle engaging the means between the spring.

and the latch, and opposing the spring, the means comprising two overlapping plates, each of which has an end pivotally engaging the other, the ends being spaced, the spring bearing directly on one plate between the pivots and the handle bearing directly on the other plate, the first men tioned plate having. a contact portion and the second mentioned plate engaging the latch.

WILLIAM H. FRANK. ELWOOD T. PLATZ 

